For job shop type made-to-order products such as an industrial machine and a motor, a production plan or manufacturing instructions have to be determined in order to manufacture the products by a delivery date a customer has requested.
For example, Japanese Patent Application Laid-Open Publication No. 2004-295679 describes a technology for, for the purpose of observing a delivery date, performing manufacturing instruction so that in-process parts can be processed in ascending order of delivery-data allowances each of which is calculated as a ratio of a remaining treatment time it takes to complete a final process to a remaining time left by the delivery date.